Aerosol cans have been in widespread use for a variety of applications. Aerosol cans are also used to accommodate mounting foam or polyurethane foam which in the building trade are indispensable materials for insulating and sealing purposes on windows and doors.
Aerosol cans of this type have a valve arranged on their upper end, the so-called can dome, via which the can content is discharged when said valve is actuated. From the valve the can contents is conveyed through an attached tube and, if applicable, a continuing trunk, on to the targeted site where it exits and is used as mounting foam. Conventional aerosol cans frequently require that the valve is actuated almost directly on the conveying tube itself which renders handling and use of the can rather uncomfortable. In particular, the can and its conveying tube must be positioned close to the point of discharge, following which the valve must be pressed which often may be quite difficult due to poor accessibility of the destination site.
To enable aerosol cans to be handled more easily the known art has proposed adapters that can be attached to the dome of the cans. Accordingly, the German patent specification DE 35 18 627 C3 discloses an apparatus comprising an adapter part to be connected with a spray gun on one end and screwed onto the aerosol can on the other end by making use of suitable connecting means. In this case, however, a separate adapter part is needed which makes can handling more complicated.
Furthermore, there are other adapters known from prior art that are provided with a thread via which they are screwed onto the aerosol can. However, the provision of such a thread always has disadvantages in that, firstly, fabrication of the adapter is comparatively intricate and expensive and, secondly, such an adapter has to be exactly adapted to the given aerosol can to make sure it fits the can correctly. Moreover, mounting foam often enters the thread spaces where it hardens and impairs the tight seating of the components due to the fact that the foam volume increases significantly so that the adapter can be removed only with difficulty and reused only after it has been thoroughly and laboriously cleaned to remove undesirable foam remnants.
In DE 43 13 319 A1 as well an adapter for mounting foam containing aerosol cans has been described. It is the objective of that invention to provide means keeping the contents of the can fresh and usable as long as possible in that the tube serving for mounting foam discharge purposes is designed so as to be capable of being folded back on itself in the form of a ‘squeezing knee’. The actuating device shown there has a nozzle pointing downwards and being provided with an inner space of truncated-cone shape through which the can content shall be discharged. By actuating a handle provided on the adapter the nozzle is bent towards the valve in such manner that pressure is exerted on the valve stem causing the valve to open. To be able to actuate the valve the nozzle of the adapter is usually placed on the can in an oblique position and by pressing the handle is brought in a more perpendicular position over the can so that through the force exerted on the stem the valve can be opened.
This prior-art apparatus has the disadvantage that the force resulting from actuating the handle cannot be applied to the stem perpendicularly from above but acts on it obliquely which causes the valve to open in a non-uniform manner. Furthermore, forces exerted in order to actuate the valve always act also on the seal arranged between the nozzle and the valve.